Among panel display devices, the Thin Film Transistor Liquid Crystal Display (TFT-LCD) has advantages such as small size, low power consumption, relative cheap cost and free of radiation, and accordingly holds a dominant position in the current panel display market.
At present, regional displaying function can be implemented in the TFT-LCD. Taking a cellular phone as an example, when a protective casing for the cellular phone is closed, some general information such as time information, weather information or incoming call information can be displayed on a region of the screen of the cellular phone where corresponds to a window of the protective casing, while other regions of the screen of the cellular phone are in black. In this way, the user can perform some basic operations without opening the protective casing, for example, may answer an incoming call or check the time information, weather information, messages, etc.
The conventional technology has the following disadvantage. The whole screen of the TFT-LCD operates in a full power consumption state during the regional displaying, which results in high power consumption of the display device.